Pulp Fiction

Unforgiven

Way of the Gun

Can't really narrow it down to just three but The Shawshank Redemption would be one of them.

Interstellar
Inception
Sam Raimi's Spiderman 1

Butch Cassidy and the Sundance Kid (my most favorite ending)
Some Like It Hot
The Godfather Part I

Also (to name a few others):
The Usual Suspects
Citizen Kane
Bonnie & Clyde
Planet of the Apes (1968)
Fight Club
12 Monkeys
One Flew Over The Cuckoo's Nest
Psycho
Carrie
The Graduate
Casablanca
Hana-Bi
Brazil
The Taking of Pelham 123 (1974)
Charley Varrick
Don't Look Now
Midnight Run
Chinatown
Out of Sight
Road to Perdition
The Fabulous Baker Boys
The Italian Job (1969)
To Live and Die in L.A.
French Connection II
Arlington Road
The Silence of the Lambs
Cowboy Bebop (Anime series)

Ha ha ha. Basically just type "Entire movie industry/history" and be done with it. =P

No. These are just the movies from my DVD collection with great endings. Even my collection of around 900 movies is just a tiny fraction of the entire movie history. My list also shows that you can count today's movies with great endings on one hand.

It was just a joke because you included so many titles... -__-

I know.  But what can I do, I just love movies (and the current state of the western movie industry gives me headaches).

Independant movies is where it's at, mostly, these days. 

The western movie industry is overall extremely formulaic now and lacks ambition and inspiration. Everything is made according to a formula and the movies are in turn very predictable. It's an industry that has fewer and fewer visionaries. That being said, just like with gaming, the visual aspects/technical side of the productions are really top notch now. But if you want to find a movie with a soul and heart, you'll be searching for quite a bit before finding anything.

1. Rocky
2. Return of the King
3. Top Gun